This invention relates to preparation of polyphenols, more particularly to the preparation of polyphenols from ketones or aldehydes and phenols.
Acid-catalyzed condensation of phenols with aldehydes or ketones is well known. Acid catalysts include acidic ion exchange resin catalysts and soluble acid catalysts. Soluble acid catalysts can be, for example, hydrogen chloride, sulfuric acid, hydrochloric acid, phosphoric acid, hydrobromic acid, nitric acid, dimethyl sulfate, sulfur dioxide, 4-toluenesulfonic acid, boron trifluoride, alkanesulfonic acids, boron trifluoride complexes and other acid-acting compounds, including compounds which are hydrolyzed by water to form acids, e.g. aluminum chloride, sulfonyl chloride and phosgene.
A number of compounds are known to promote such an acid-catalyzed condensation. These promoters include mercaptan groups which are either free or bound to a resin. Alkyl mercaptans and bis-mercaptoethanolamine are examples of reported promoters.
It has been proposed by Scriabine et al. (U.S. Pat. No. 2,923,744) to produce Bisphenol A using sulfuric acid, promoted by mercaptoalkanesulfonic acids or salts or corresponding sulfonate esters at a level of 0.1-5% by weight of the base charge, to catalyze condensation of acetone and phenols, when used in amounts of 0.1 to 5 percent by weight based on total charge. Sulfuric acid is used in amounts of about 2 moles per mole of acetone.
Riemann et al. (U.S. Pat. No. 4,675,458) have proposed making 9,9-bis-(4-hydroxyphenyl)fluorene in the presence of sulfuric acid, preferably concentrated sulfuric acid, and a mercaptan, particularly 3-mercaptopropionic acid, as promoter.
Massirio et al. (U.S. Pat. No. 5,248,838) have disclosed the use of a combination of methanesulfonic acid and a mercaptan/mercaptoalkanoic acid for catalyzing the condensation of phenols with fluorenone. High levels of methanesulfonic acid with respect to the feed and the mercaptan/mercaptoalkanoic acid, are used. The reactions can be run in halogenated hydrocarbon solvents.
Bottenbruch et al. (U.S. Pat. No. 4,996,373) have proposed a process for producing dihydroxyaryl compounds from carbonyl compounds and phenols under high pressure, in the presence of various catalysts, including sulfonic acid resins. Catalysts containing sulfhydryl functionality, e.g. ion exchangers treated with mercapto compounds, have been disclosed for this use.
Meyer et al. (U.S. Pat. No. 4,387,251) have proposed processes for making 4,4'-dihydroxydiphenyl alkanes using aromatic sulfonic acids as condensing agents. Mercapto groups are included within the definition of R.sub.3 and are characterized as being inert. Freitag et al. (5,210,328) disclose using the same types of sulfonic acid catalysts for making cycloalkylidene bisphenols.
Jansen (U.S. Pat. No. 2,468,982) has proposed preparation of bisphenols using anhydrous hydrogen chloride in combination with a mercaptoalkanoic acid, which may be formed in in situ by reaction of a mercaptol with the ketone, as condensing agent.
Knebel et al. (U.S. Pat. No. 4,931,594) disclose the use of large amounts of sulfonic acid resin, mixed with uncombined 3-mercaptopropionic acid, to cause the condensation to occur.
It has been proposed in British Patent 1,185,223 to use a mixture of insoluble resins, one a sulfonic acid resin and the other a resin containing mercapto groups, for making bisphenols.
Randolph et al. (U.S. Pat. No. 5,212,206) disclose a catalyst, made by treating a sulfonated ion-exchange resin with a dialkylaminomercaptan. Other references, representative of references on modification of sulfonic acid ion-exchange resins, include Wagner (U.S. Pat. No. 3,172,916). McNutt et al. (U.S. Pat. No. 3,394,089), Faler et al. (U.S. Pat. Nos. 4,455,409; 4,294,995 and 4,396,728); Heydenrich et al. (U.S. Pat. No. 4,369,293); Berg et al. (U.S. Pat. No. 5,302,774) and Maki et al. (U.S. Pat. No. 4,423,252). The reactive catalysts generally include mercapto-functions attached to a sulfonic acid group in the form of a sulfonamido or ammonium sulfonate salt.
Shaw (U.S. Pat. No. 4,859,803) discloses preparing bisphenols from phenol and a ketone in the presence of an acidic (sulfonic acid) ion-exchange resin and a mercaptan, the mercaptan being added at particular locations of a specified reactor configuration to prevent the formation of cyclic dimers.
Li has disclosed (U.S. Pat. No. 4,825,010) isomerization of by-products of condensates of phenols and ketones, using a catalytic amount of acidic sulfonated cationic-exchange resin having sulfonic acid sites ionically bonded to alkylmercaptoamines. Other patents by Li (U.S. Pat. Nos. 4,822,923 and 5,001,281) further suggest the state of the art of using ion-exchange resins to isomerize by-products of bisphenol syntheses.
Powell et al. (U.S. Pat. No. 5,105,026) disclose using acidic ion-exchange resins to isomerize undesirable products of bisphenol synthesis to desirable products, e.g. to Bisphenol A. Morgan (U.S. Pat. No. 3,546,165) has disclosed condensation of phenol with various ketones, including fluorenone and indanone, using high levels of hydrochloric acid or hydrogen chloride, in the presence of minor amounts of 3-mercapto-propionic acid. The products are used for the preparation of polyester resins.
Szabolcs (U.S. Pat. Nos. 4,467,122 and 4,503,266) discloses washing crude product, containing BHPF, from a hydrochloric acid/zinc chloride catalyzed process, to remove HCl, ZnCl.sub.2 and excess phenol, prior to recrystallization from dichloroethane. See also the abstract for DE OLS 2,948,222 (Jul. 30, 1981).
Korshak et al. (SU 172,775) disclose washing a mixture of phenol, BHPF and HCl with water, after which phenol is removed by distillation.
The following references, herein incorporated by reference, disclose the preparation of resins, containing sulfonic acid functionality, introduced either by copolymerization or by sulfonation after polymerization:
______________________________________ U.S. Pat. No. 3,205,285 Turbak et al. U.S. Pat. No. 3,366,711 Mazzolini et al. U.S. Pat. No. 3,426,104 Masson U.S. Pat. No. 4,587,304 Thaler et al. U.S. Pat. No. 4,764,557 Eichenauer et al. ______________________________________
Trapasso (U.S. Pat. No. 3,706,707) discloses the preparation of adducts from a polymerized cyclic ether and a sultone. Dean (U.S. Pat. No. 4,568,724) is of similar interest with respect to reaction products from an EPDM rubber and a sultone.
Welch (U.S. Pat. No. 3,029,221) and Niwa et al. (U.S. Pat. No. 4,912,170) disclose processes for modifying polystyrene resins.
It is an object of this invention to provide a process for the condensation of aldehydes or ketones with phenols, to achieve high yields of preferred bis-(4-hydroxyaryl) isomers with low reaction times while avoiding use of strong inorganic acids.
Further objects of the invention include the development of processes for the synthesis of polyphenols, characterized by high yields of high purity products under reaction conditions, which are not corrosive to vessels in which the processes are conducted. In addition, avoiding the use of sulfuric acid, eliminates the possibility of side reactions, including sulfonation of phenols.